f Interpretation of geoelectric anomalies by the fourier analysis

The resistivity profile technique is an efficient method to detect lateral inhomogeneities at depth. Such a method has been commonly applied to investigate shallow structures, as Bink-holes, fractured zones and archaeological features. On the other hand, the anomalies obtained are of small amplitude and high frequency content. A process to improve the signal/noise ratio is based on the application of the Fourier Transform (Orlando et al, 1987). Cámara et al (1990) showed that a separation between long amplitude and small amplitude resistivity anomalies could be performed by a filtering proces in the frequency domain with succesful results. The first one was called a regional and the second one a residual. The present paper involves two aspects.